1. Field of the Invention
This invention relates to multi-contact electrical connectors used for interconnecting and disconnecting conductors in which two or more of the connectors can be selectively shunted, and more particularly to modular connectors used to interconnect and disconnect equipment to a telephone network.
2. Description of the Prior Art
Multi-contact modular conductors consisting of standard plugs and jacks are commonly used to connect telephones, data processing equipment, and similar equipment to a switched telephone network. One type of connector used for this purpose consists of a four, six or eight position connector assembly including a jack which would normally mate with a mating plug attached to the equipment to be added to the telephone network. One such electrical connector receptacle or jack is disclosed in U.S. Pat. No. 4,193,654. That Electrical jack consists of a housing, having a longitudinally extending cavity profile to receive a companion plug. A plurality of contact elements or terminals are positioned in the jack housing with deflectable cantilever portions extending into the cavity. The remaining portion of the contact elements or terminals are secured to the exterior of the housing and are formed for receipt into a printed circuit board at the opposite end of the contact elements from the cantilever portions located within the housing. Receptacles or jacks of this type can be constructed to receive any number of contact elements and are conventionally constructed with four, six or eight contact elements. These conventional receptacles have a keying profile for keying the plug relative to the jack so that the contact terminals and the plug will be in alignment with the contact elements in the jack or receptacle. Thus it is possible to insert a plug having six terminals into a housing having eight contact terminals. Conventional receptacles and jacks of this type are constructed with terminals and contact elements on center lines such that a six position plug will be appropriately keyed to engage the six innermost contact elements on an eight position jack.
Defensive publication T961,003 discloses a female connector or jack having a row of side-by-side contact springs. These contact springs can be positioned in a conventional eight position jack to make contact with a four, six or eight contact plug. Additional switch contact springs are positioned adjacent the two ends of the row of contact elements. Each pair of additional springs on each end includes a movable contact spring and a stationary contact spring in engagement with the movable contact spring. Insertion of a plug having a width greater than the extent of the eight innermost principal contact elements will deflect the movable contact spring thus opening the switches on either end. The switch springs positioned at either end of the row of contact elements are connected by wires to common terminals to bridge selected contact elements. For example, one switch can bridge the terminals in the first and fourth position of an eight contact row. By attaching wires from the stationary contact spring and the first contact element to a termination and by securing wires extending from the movable contact spring and from the fourth position to a separate termination, the first and fourth contact elements will be bridged so long as the two switch contacts remain in contact. U.S. Pat. No. 4274691 discloses a modular jack assembly having contact elements extending diagonally into a plug receiving cavity of a modular jack. The contact springs are pivoted about the front end of the cavity which receives a companion plug. Shorting elements extend through the housing and are positioned at the rear of the plug receiving cavity. The spring contact elements are normally resiliently flexed to engage the shorting elements until a plug is inserted into the cavity to deflect the contact elements away from the rearwardly exposed shorting elements.
Specifications intended to insure compatibility of equipment incorporated into a switched telephone network require that eight position jacks used in certain systems have the capability of bridging two or more of the individual contact elements. For example, in certain situations an eight position jack must maintain a series connection to tip and ring conductors of a telephone line. If additional jacks are to be positioned in series with this jack, it is necessary that these tip and ring conductors be bridged through each jack in order for equipment inserted into any one of these jacks to properly function when the other jacks remain vacant. For example, some applications require that conductors in the first and fourth positions be bridged to maintain series continuity for the ring conductor through the unoccupied telephone jack and that contact elements in the fifth and eighth positions be bridged to maintain series continuity for the tip conductors through the unoccupied telephone jack.
If a six position plug were to be inserted in this eight contact jack, series continuity to the other telephone equipment or other telephone jacks could only be maintained if the bridged contact elements remain shorted. If an eight position plug were inserted into the jack, the bridged contact elements must no longer be bridged since it is necessary to establish a series connection for both the ring tip conductors through the equipment connected to the jack by its attached eight position plug. At present no known jack otherwise having the configuration of a standard eight position jack possesses this capability. The jack depicted in U.S. Defensive Publication T961,003 establishes such disconnectable bridge connection by adding additional contact elements in the form of spring contacts which must in turn attached to appropriately positioned contact elements by external wires. Furthermore, none of the prior devices provides a shunted modular connector according to the type represented by the preferred embodiment disclosed herein, in which the contact elements in the modular connector are attachable at discrete points to an external path. For example, none of the prior devices is adaptable to be attached to discrete paths on a printed circuit board while retaining the capability of establishing a bridged connection, when a plug having a width less than the lateral extent of the row of contact elements is inserted into the receptacle; while disrupting the bridge connection when a plug having a width greater than the lateral extent of the contact element row is received within a plug receiving cavity of the receptacle or jack.